Prevalence and topographical characteristics of keratoconus in patients with refractive errors in the Egyptian delta.

PURPOSE: To study the prevalence of keratoconus (KC) and the topographical characteristics of the affected corneas in patients with refractive errors who were seeking refractive surgery in the Egyptian delta. METHODS: A retrospective study covering four and half years (Jan 2012-June 2016) where the topographical data of 8124 participants were obtained from the records of a refractive center in the Nile delta region, Egypt. The diagnosis of KC was based on the Holladay criteria in one or both eyes, using the Pentacam scans, whereas grading of KC was based on the Amsler-Krumeich classification. RESULTS: The prevalence of KC was 1.12% (91/8124 participants) with 95% confidence interval 0.91-1.3. Of all the affected cases, 5 cases (5.5%) had unilateral, and the other 86 cases (94.5%) had bilateral KC. The affected and unaffected subjects did not show any significant difference regarding gender. Sixty-eight (38.4%) eyes had stage 1 KC, 53 eyes (29.9%) had stage 2, 27 eyes (15.3%) had stage 3, and 29 eyes (16.4%) had stage 4 KC. It was most prevalent (1.2%) among cases with astigmatism (P < 0.001). CONCLUSION: Keratoconus was found in 1.12% of patients seeking refractive surgery, with no gender preference. Most cases had bilateral affection. Astigmatism was the most common refractive error to be associated with keratoconus.

RECALCITRANT CYSTOID MACULAR EDEMA AFTER PARS PLANA VITRECTOMY.

PURPOSE: To evaluate the outcomes of different types of treatment of chronic cystoid macular edema (CME) after pars plana vitrectomy. METHODS: Retrospective review of eyes that developed chronic CME after pars plana vitrectomy treated with intravitreal triamcinolone acetonide (TCA) with or without the addition of anti-vascular endothelial growth factor. RESULTS: Thirty-nine eyes of 37 patients were included, with a median duration between pars plana vitrectomy and onset of CME of 5 months (interquartile range, 3-12). In most eyes (66.7%), the main indication for surgery was for vitreomacular interface disorders, such as epiretinal membrane, vitreomacular traction, and macular hole. With intravitreal TCA, there was a significant decrease in central foveal thickness at 3, 6, and 12 months, compared with baseline (P = 0.0171, 0.0401, and 0.0024, respectively). A significant gain in vision was noted at 1 month compared with baseline (P = 0.0169), but this was not sustained at 3, 6, and 12 months (P = 0.4862, 0.9098, and 0.4312, respectively). The addition of bevacizumab to TCA did not provide any additional benefit for central foveal thickness and visual acuity. Thirty-two eyes (82.1%) were started on prophylactic antiglaucoma drops 2 weeks after a TCA injection, and no eye needed laser or surgery to control intraocular pressure. CONCLUSION: Chronic CME after pars plana vitrectomy is recurrent and difficult to treat. Intravitreal TCA is effective in reducing CME, but there was only short-term visual acuity improvement even with continued reduction of central foveal thickness. Intraocular pressure did not significantly rise with the use of prophylactic antiglaucoma drops even with repeated injections.